//0x1234
//0000 0000 0000 0000 0001 0010 0011 0100
//大端存储为 00 00 12 34
//unsigned char 取 00

//小端存储为 34 12 00 00
//unsigned char 取34
//内存操作单位是字节，所以是34而不是43
#include<stdio.h>
int main()
{
        unsigned int a = 0x1234;
        unsigned char b = *(unsigned char*)&a;
        printf("%x", b);
        return 0;
}